/Engine/Source/Runtime/OpenGLDrv/Public/OpenGLDrv.h
virtual void RHICopyBufferRegion ( [FRHIBuffer](API\Runtime\RHI\FRHIBuffer) * DestBuffer, uint64 DstOffset, [FRHIBuffer](API\Runtime\RHI\FRHIBuffer) * SourceBuffer, uint64 SrcOffset, uint64 NumBytes )